The present disclosure relates to field of building exterior walls and optical devices, and in particular to a reflectivity adjustable wall unit, a wall module, and an intelligent building exterior wall system.
Currently, facades of many high-rise buildings are decorated with glass. For aesthetic reasons, many glass facades are constructed with mirror materials of high reflectivity. In this way, under the scorching sun, strong light reflected by shining glass walls will have a serious impact on pedestrians and drivers outside the buildings. Dazzling reflection not only damages visual organs, but also brings inconvenience to traffic and impairs driving safety. The dazzling reflection from taller skyscrapers may even affect aircraft flight safety. White light pollution has become a new unnatural urban hazard.
Recently, electrochromic glass has been used as an external wall in intelligent buildings. The electrochromic smart glass can adjust its light absorption and light transmission under action of an electric field, and can selectively absorb or reflect external thermal radiation and internal heat diffusion, thereby reducing the amount of energy that office buildings and residential homes consume during the summer and during the winter. However, according to ordinary usage habits, sunlight is stronger in the summer and people indoors prefer to reduce incidence of hot light from outside. The electrochromic glass is consequently adjusted to increase reflection and reduce incidence, so as to bring down indoor temperatures. However, for ambient environment outside the wall, increased reflection off of buildings in strong summer glare can result in serious light pollution. Meanwhile, light absorbed by the electrochromic glass will also be converted into heat. This heat is eventually transmitted into the building, where it burdens building air conditioning systems.